Operating Systems
Operating Systems
Operating systems - they’re behind everything, somehow, but what are they?
An operating system (OS) is a computer program, a piece of software, that manages and organizes all of the other software on a computer. You may have a web browser and a text editor and an email application open, and the operating system keeps track of all of them and makes sure they can work at the same time.
Another important thing operating systems do is bridge the gap between hardware and software. When writing code, you almost never have to consider the exact hardware of the computer that will be used to run it. The operating system handles that part for you.
Operating systems also keep track of users. If multiple people can use the same computer, the operating system is what keeps track of who is using the computer, what files they are permitted to access, and what they can do.
Operating systems also contain the filesystems, which organize the information on a computer, using files. There are a number of attributes to a file, such as a name, size, type, and location. There are limits to both the size of files and the number of files a computer can have, but they are high enough to be almost always irrelevant.
The kernel is the central part of the operating system which handles its key tasks. Notably, it is responsible for controlling what programs use the computer’s hardware, including the CPU and memory.
Common Operating Systems
The most common operating systems are Microsoft Windows, MacOS, and Linux. Windows is the most widely used on personal computers, and it is maintained by Microsoft. MacOS is maintained by Apple. Linux is an open-source operating system which predominates on mobile devices and servers. It is available in various distributions or distros which are more specific variants of Linux that you can install on a computer as your operating system. Examples include Ubuntu, Debian, Fedora, and Arch.
MacOS and Linux are both based on Unix. Unix was an early operating system, and is now a family of related operating systems. MacOS is considered to be a Unix system, whereas Linux is Unix-like. This effectively means that they work similarly in some ways. Some other terms you might come across are GNU, which refers to part of Linux, and BSD, which is a related operating system. When learning about operating systems and anything written above, they’re generally going to fall into this Unix-based category and work similarly, unless it’s Windows.
For typical everyday usage, these will all work basically the same, with some variations in the user interface. Windows is used very widely, in homes, education, and businesses. There are a ton of applications, games, and support available for anyone using it. Many games and specific applications will not run on MacOS or Linux, only Windows. MacOS is only available on Apple’s computers, whereas Windows and Linux will run on a wide variety of computers. In my experience, MacOS and Linux are often preferred for programming and doing particular computer-y tasks, but Windows can also be used for the same tasks. Linux has traditionally been less reliable than the others and requires some technical knowledge to use, but has improved greatly. Some Linux distributions are easy to use, while others require more DIY from the user and can become a hobby to enthusiasts.
There are different operating systems because they were developed by different people. There was no standard agreed on for exactly how a computer was going to work. There were different companies and groups using different hardware which created operating systems which have completely evolved and changed over time.
Alternate Explanations
Here are some other websites which I thought also did a good job introducing the topic.